Fuel pump for combustion engines



Jam ll i927.

M. ST CLAIR FUEL PUMP FOR COMBUSTION ENGINES Filed August '7,

1922 2 Sheets-Sheet 1 m10 0 Ea u 1927 M. sT. CLAIR FUEL PUMP FOR COMBUSTION ENGINES Filed August '7, 1922 2 Sheets-Sheet 2 7 5 8 5 /w v w 9 f 5 F i.. m m w 7 l ||.....r.. M m M 85 A. Z4 Twoomud V. 0J l 55 4 6 www@ l .M da A uzxfz i E: 5. fr@ wm kw* /1 M QU m I. WM/ m5 m w holding the member Patented Jan. i1., i927.

PATENT OFFICE.

-v uorrar sr. CLAIR, or darm, on'raaro, CANADA.

FUEL P Unir ron coMBUs'rIoN iiNeiNns.

Application filed August 7, 1922. Serial No. 580,361.

The principal objects of the invention are, to efect a very positive feed of the fuel oil to the engine in a definitclymeasured quan- -tity thereby ensuring positive and uniform conditions in fuel supply.

The principal feature of the invention consists in the novel arrangement of a valve within the plunger of a pump and of the means for regulating said valve whereby the etijective pressure stroke of the plunger is varied.

In thefdrawingsFigure 1 isgavertical sectional view through the pump showing their plunger inl itsoutward position.- 'l

i ing t e 'plunger intheinward ,position and illustrating the.' restricting action of the Imetering valve. j Figure-.Bis a vertical sectional view 'throughthe valve portion ofthe plunger illustrating the mechanism for regulating the metering device. Y

Figure 4 is a horizontal sectional view through the line 4-4 of Figure 3.

Figure 5 is a sectional detail illustrating a modified construction of valve regulating `mechanism.

In the operation of hydro-carbon engines the greatest vd itiiculty to overcome has been the regulation of the amount of fuel injected into the cylinder at each stroke. This invention has been devised to accurately regu- `late the amount of fuel. discharged into the cylinder at each stroke of the piston and to enable such charge to desired.

In the construction illustrated the pump is formed with a circular casing 1 which s urrounds the timing shaft 2 upon which is mounted the pump operating cam 3.- The pump frame extends in an enlarged open structure 6 above the cylindrical oriiice 4 and in the upper end thereof is secured a cylindrical member 7 which is connected by a pipe 8 to a suitable fuel supply. The lower end of the member'7 is provided with a packing gland 9 through which the plunger rod 10 slides.- The lower end of the rod is threaded into thepiston guide A5.

A spiral compression spring 11 encircles the rod between the 5 inwardly in'yielding en agement with the cam 3. glhe cylindrical member 7 is seated against re 2 isa vertical v'sectional view showv the bottom of a cylindrical chamber 20 and bevaried as may be gland and the-member 5.

a shoulder 12 and a cap 13 is threaded on the upper end of the member 6 and engages the upper end of the member 7 holding it secure y in place.`

`.A cylindrical flange 14 projects inwardly from the" cap-extending into the interior of the cylinder v7. The cap 13 is formed with a central cylindrical chamber 15, theupper end 16 of which is reduced and threaded and in this threaded end is secured a lcylindrical member 17 having a central passage 18-which `forms the actual pump cylinder. f Toward the up l dper end of the central passage 18 1s forme Aa tapered valve seat 19 at within this chamber is arranged a valve 21 ground to a sliding fit. and having a tapered seat at the bottom end to en age the seat 19.

The side walls of the va ve 21 are. pro- 'vided with longitudinal grooves 22 extending from the seat to the top.'

`A nipple `23 is threaded in the upper end of the'member 17 and is adapted to receive a pipe connection which leads to a suitable spray nozzle which sprays the oil into the engine cylinder. A- coil compression spring 24 is arranged between the nipple 23 and the valve 21 and is adapted to retain the valve on its seat but which will lift under a predetermined pressure.

The pump plunger is in the form of a tubular member25 Awhich is a sliding fit in the central passage 18 and has an enlarged `lower end-26 which is threaded on to -the enlarged upper end of the plunger rod 1'0.

Within the plunger rod 10 is formed a cylindrical valve chamber 29 having a tapered seat 28 on its lower end. A valve 29* ground to a sliding it in the chamber 29 and having grooves 30 in the side wall to allow the passage of oil is formed with a ground tapered seat 31 to engage the seat 28.

A iuted stem 32 extends downwardly from the valve seat into a reduced cylindrical passage '33. This passage has opmmunicationwith the interior of the cylinder 7 through a pair of longitudinal slots 34 through which the oil liows.

Surrounding the plunger rod 10 within the cylinder 7 is a collar'35 formed with an annular groove 36 and in this collar is secured a pin 37 which extends transversely through the slots 34 and is adapted to en.-A

gage the bottom end of the stem 32 of the valve 29.

a The position of the pin 37 in relation to the valve is regulated by an jarm 38 formed with a yoke end 39 which lits into the groove; 36. The arm extends laterally through 'a- VThe outer end of the arm 38 is formed with a sleeve end 42 encircling the spindle.

414 and is provided with a notch 43.

, A nut 44 threaded on the spindle 41 is provided with a lug projection 45 adapted to engage the notch43 in the sleeve end of the arm 38, lthusforming a positive adjustable connection between the arm and the The outer end of the spindle is provided with an operating lever 46 which is operated to control the position ofthe collar 35 on its pin 37. In the construction shown in Figure 5 the grooved collar 35 which carries the pin 37 for regulating the metering valve, is operated by a forked member 47 forming 'part of a sleeve 48. The sleeve 48 is slidable on a spindle 49 which is arranged parallel with the pump cylinder and is spring held by the spring 50. Within the lower threaded end Aof the sleeve 48 is threaded a member 51 which bears upon an eccentric 52150 that the rotation of the eccentric raises or lowers the sleeve and consequently the collar 35. The spindle 49 is formed with a squared end 53 slidable in a squared hole in the member 51 so that the rotation of the spindle adjusts the member 51 in relation to the collar 35. 'Ihe spindle is' provided with a knurled head 54 and a tapered seat 55 renders the spindle oil tight without packing.

In the operation of this device the oil is fed throughthe pipe 8 to the cylinder 7 and it completely fills the cylinder and enters the central orifice in the plunger through .the slots 34. I

The collar 35 is provided with holes 47- to ensure the free tiow of'oil to the centre'of war bearingv thereon' is moved upwardly or;

downwardly according to the position of the cam. In Figure 1 the parts are shown in position at the maximum point of discharge, that is to say, the guide 5 is resting on the apex -of the'cam. and the top 'end of the plunger has .reached its maximum position, the valve 21 being closed. As the cam continues to rotatethe'plunger moves dawn-A wardly through the action of the spiral spring 11 andthe suction created by the downward movement of the plunger causes .the pija-n the' langer when the plunger moves up." (ily througlithe collar and the slotsare* closed thereby.

and the oi-lf'lows upwardly through the grooves 3Q lin the head of the valve to the central passage in the .plunger 25.

'l`li'e' .eylinder'ofjthe pump, that is, the 'space fahove'the tubularplunger '25 is full "the entire central passage 'i will 1 flow.r baci; through the pastthez valve 29a until er r1ses.. ojfthe' point where the is then. immediately checked and the further micommences toA raise the movementupward of the Vplunger results inthe pressure of the oil being exerted to lift the .upper-'valve-2I and force the oilv through the grooves 22 and on through the nipple-'23 and; its. connecting pipe. This feature is the vital part of the invention. By themanipulatingofthe'lever 46 or of lthe spindle;- 49, whicheverconstruction is used, thegcollar 35may be adjusted tofany` .desired .position in the stroke of the pump .so that the -effective strokeof the pump 1n pushingthe oil through the 'connecting pipes to the engine may lie-regulated. tov any desii-esl length ranging from maximum to zero. Such a regulation of fuel is found to be extremely valuable-in the proper operation of an oil burning engine and the extreme simplicity of the structure ensurespositive operation and dependability:

lYhat I claim as my invention isz;

1. In a fuel pump-(for vcombustion engines, a compression cylinder, a valve closing the discharge end of said compression cylinder, a plunger operating in said cylinder in sealing contact with the walls thereof and having ya central .passage therethrough .openat the top, a. valve arranged entirely -within the plunger and enclosed thereby and operated by the inward iiow of oilfr'om .the open top to close said central passage, passages to permit the flow of oil pastthe valve when it is raised from its '-lseat, and means co-operating -with vsaid plunger'valve through the side wall of said plunger :tohold said plunger valve from its seat for varying the effective stroke of the plunger...

.2. In a' fuel pump for combustion eng111es,.a .cyl1nder, a valve closing the discharge end ot said cylinder, a plunger 'opl erating.' in said cylinder and having a-central passage therethroughl open 'at the top, a valveairanged wholly within and enclosed by the plunger and'operated bythe inward flow of oil-from the opentop`to close said central passage, longitudinal slots in the side wall of said plunger, -an adjustable sleeve member encircling the valve enclosing netsnoeportion of said plunger, a pin carried by said sleeve member and adapted to enter said slots and engage said plunger valve to hold WAit from its seat during the initial part of the stroke of said plunger.

3. In a fuel pump for internal combustion engines, a casing having a cylindrical upper portion, a removable cylindrical member disposed in the upper portion of said cylinder and having a downwardly extending portion provided with a packing nut, a cap member threaded on the outer end of said cylinder closingthe upper end of said cylindrical member and engaging the same to hold it in place, a compression cylinder secured to said cap, a plunger working in said compression cylinder and extending downwardly through Said cylindrical member and packing nut, means for bye-passing the oil from the top of said compression cylinder back through said plunger to the interior of said cylindrical member, a valve in said plunger for regulating said backflow, means for feeding fuel to the interior of said cylindrical member, and a valve closing the outer end of said compression cylinder.

4. In a fuel pump for internal combustion engines, a easing having a cylindrical upper portion, a cap member secured upon the outer end of said cylindrical upper portion, a cylinder supported by said cap member, a hollow plunger sliding in said cylinder and adapted to seal the cylinder walls and having an enlarged removable hollow inner end, a valve arranged within the hollow portion of said plunger and adapted to close the passage therethrough, slots in said plunger below the valve, a sleeve slidable on the slotted portion of said plunger having a pin extending transversely through said slots and adapted to engage said valve to hold it from its seat during a portion of the stroke of said plunger.

MOFFAT ST. CLAIR., 

